Although the exact number of buried landmines is unknown, it is estimated that there are millions of landmines buried in more than seventy countries around the world. Landmines kill or maim over 4000 people every year, often years after hostilities have ceased.
Generally, besides manually clearing landmines, which is slow and hazardous, mechanical means are used for demining. Mechanical tools are designed to deliver sufficient force on the ground to detonate a typical landmine buried about 200 mm underground and to deflect the explosive force. What follows is an overview of some of the main mechanical technologies currently in use today.
Chain flails are by far the most used mechanical means for demining. The chain flail has a central drum rotating at high speed with chains attached to it. The chains carry weights of varying geometries at their free end. As the drum rotates, the end masses strike the ground and deliver a large impact force capable of detonating landmines.
Tiller and roller machines operate on the same principle as the chain flails, with a central drum rotating at high speed that carries hardened chisels or teeth. On plowing through the ground, the rotating teeth strike the ground above the buried landmines, jolting the ground with sufficient force to trigger detonation of the landmines.
There are also hybrid or combination systems that use two or more demining methods in order to increase the neutralization efficiency. These systems are still in the development stage. One uses a set of hydraulic cylinders provided with feet that impact the ground causing detonation of the landmines. The second further crushes any remaining explosive.
These mechanical system suffer from various shortcomings.
Firstly, these mechanical system require a lot of maintenance. For reliable and efficient operation of mechanical demining machines, maintenance and cost are important. Impact tools, such as chain flails and tillers, require frequent maintenance and replacement of parts of worn or damaged parts. Machine downtime is high, and part replacement costs are also high.
Presently available demining machines are severely limited by terrain and weather conditions in a given mine field.
Present demining machines, such as tillers, require powerful engines to drive the tiller drum and the prime mover. This creates problems of mobility, soil compaction, as well as transportation problems.
From the above, it is evident that there remains a need in the industry for more efficient demining techniques that do not give rise to at least some of the issues described above.